Frozen confections such as ice cream, ice milk, frozen yogurt, sherbet, sorbet, glace, gelato and granita have a long history of manual delivery by means of hemispherical scoops. Thus in the minds of consumers these products are associated with round and in particular spherical shapes. Mass production of spheres of frozen confections poses a variety of challenges not only mechanically but also for the visual appeal of the final product, and for its mouth feel.
Preformed balls represent a potentially ideal form for plating and presentation, however they have little if any presence in the market. Partly this is because attempts at molding these balls, e.g., between two hemispherical cavities, have yielded product that has been criticized as too smooth at the surface and or manifesting a visible seam line from the mold joint. In addition they may become modestly deformed under the mechanical and drop forces applied by production lines. One potential remedy is to provide a final coating such as, for example, a couverture chocolate coating, to mask seam lines and other imperfections in the shape or texture, however that solution is satisfactory only when a coated product is desirable.
Various attempts have been made to improve the production speed and appearance of mass-produced round frozen confections. In some cases the aim has been to make the surface smoother. In others it has been to make it look more like hand-scooped product.
Early examples include U.S. Pat. No. 3,080,830 issued to Walter and U.S. Pat. No. 3,029,750 issued to Burt. These disclosures teach a fixed upper half of the mold with a hemispherical cavity, where the mold's bottom half is two hinged movable quadrisphere parts that allow release, and the quadrispheres are heated to maintain a liquid surface on the product to facilitate release of the shaped balls. U.S. Pat. No. 4,674,968 issued to Durst introduces a further improvement with, among other features, a rotatable arc-shaped scraper inside the mold to facilitate shaping and release of formed product without leaving tool marks.
Another illustrative apparatus for continuous manufacture is taught in U.S. Pat. No. 5,031,567 issued to Daouse et al., where a pasty mass is extruded as a roll and cut into essentially spherical portions by means of a diaphragm. The portions are deposited onto a moving conveyor belt, that carries them first through a hardening tunnel—i.e., a low temperature tunnel—and then into a machine to receive a chocolate coating.
U.S. Pat. No. 7,407,681 issued to Marchon et al. notes several difficulties with apparatus such as that of Daouse et al. The critique includes that, before being coated, the product is deformed because the spheres as initially extruded are soft and sag before they can be completely frozen. The diaphragm release mechanism also contributes to a slight teardrop shape with a point at the top, moreover the diaphragm blades leave a mark. Thus the product appears to be imperfect and is regarded as premium in quality only after the coating has been added. Modifications to overcome these effects are not economical and they leave machine marks intact: accelerating hardening by means of a super-cooled tunnel or liquid nitrogen bath.
Thus Marchon et al. teach instead a manufacturing process that produces frozen confectionary products that are said to have even roundness and over 95% cohesion, but which essentially lacks an apex, rough edges, and forming tool marks. There the product is extruded as a roll at no more than −7° C. at constant pressure but slowly enough so that there is no backpressure when it is shaped into a sphere or other round shape by a forming head at the leading edge. The forming head avoids the back pressure by alternating the product flow between two diaphragms, each of which can form a spherical or other rounded shape. The rounded surface of the frozen product as obtained is regarded as smooth, defect-free and suitable for sale of uncoated product.
However the products taught by Marchon et al. have other difficulties. Although identical appreachance and glass-smooth portion surfaces are considered desirable for premium status in the marketplace, super-premium markets prefer confection portions that appear to be artisanal and hand-made even if they are produced in volume. Thus there is an ongoing need for improvements in mass production of formed frozen confections.